Historical context
The Eudemian Ethics is Aristotle's other major treatment of ethics, parallel to the more famous Nicomachean Ethics and, the platform reads, long unjustly neglected in its shadow. Named (like the Nicomachean) probably for the editor who arranged it — here Eudemus of Rhodes, Aristotle's pupil — it covers much of the same ground: the nature of the good life, virtue, practical wisdom, friendship. Remarkably, the two treatises share three books in common (the "common books"), which appear in both, testifying to how closely related Aristotle's ethical thinking was across his works.
Central argument
The platform reads the Eudemian Ethics as offering, in places, a fuller or clearer treatment of central Aristotelian doctrines. It pursues the same core questions — what is eudaimonia? what is virtue? — and reaches broadly the same answers: that the good life is the activity of the soul in accordance with virtue, that virtue is a settled disposition concerning the mean, that practical wisdom is the master virtue. Some scholars find its treatment of certain topics — the relation of virtue to fortune, the unity of the virtues, the role of God in the good life — more developed or more philosophically interesting than the Nicomachean parallel.
Significance
The platform reads the Eudemian Ethics as important both for its own arguments and for what the two ethical treatises together reveal about Aristotle's method. That he should have written two parallel works on the same subject, sharing three books, shows the ethics as a body of teaching reworked and refined over time rather than a single fixed system. The platform reads the relation between them — which is earlier, which represents Aristotle's settled view — as one of the live questions of modern Aristotelian scholarship, and reads the Eudemian Ethics as a necessary part of any complete understanding of Aristotle's moral philosophy.
Reception and influence
The platform reads the Eudemian Ethics as the more neglected of the two for most of history — overshadowed by the Nicomachean, which became the Aristotle on ethics for the medieval and modern traditions — but as increasingly studied in recent decades as scholars have recognized its independent value. The platform carries it as the companion to the Nicomachean Ethics in the platform's treatment of virtue ethics, and as a reminder that even the most canonical philosopher has neglected works repaying fresh attention, relevant to virtue ethics today.